commit 9fb96991e63033ba963c7b1eff10e5c4f5a93b0a
author Dave Cheney <dave@cheney.net> Wed Dec 05 15:59:01 2012 +1100
committer Dave Cheney <dave@cheney.net> Wed Dec 05 15:59:01 2012 +1100
tree bf1ea0ec50108e450a7b383a09d3e66b1383913e
parent 4855c1c14589de01140087f93ecbd9153c9b1a8b

net: fix data races on deadline vars

Fixes #4434.

This proposal replaces the previous CL 6855110. Due to issue 599, 64-bit atomic operations should probably be avoided, so use a sync.Mutex instead.

Benchmark comparisons against 025b9d070a85 on linux/386:

CL 6855110:

benchmark                        old ns/op    new ns/op    delta
BenchmarkTCPOneShot                 710024       727409   +2.45%
BenchmarkTCPOneShotTimeout          758178       768620   +1.38%
BenchmarkTCPPersistent              223464       228058   +2.06%
BenchmarkTCPPersistentTimeout       234494       242600   +3.46%

This proposal:

benchmark                        old ns/op    new ns/op    delta
BenchmarkTCPOneShot                 710024       718492   +1.19%
BenchmarkTCPOneShotTimeout          758178       748783   -1.24%
BenchmarkTCPPersistent              223464       227628   +1.86%
BenchmarkTCPPersistentTimeout       234494       238321   +1.63%

R=rsc, dvyukov, mikioh.mikioh, alex.brainman, bradfitz
CC=golang-dev, remyoudompheng
https://golang.org/cl/6866050

src/pkg/net/sendfile_linux.go

diff --git a/src/pkg/net/sendfile_linux.go b/src/pkg/net/sendfile_linux.go
index 5ee18f9..3357e65 100644
--- a/src/pkg/net/sendfile_linux.go
+++ b/src/pkg/net/sendfile_linux.go
@@ -58,7 +58,7 @@
 		if n == 0 && err1 == nil {
 			break
 		}
-		if err1 == syscall.EAGAIN && c.wdeadline >= 0 {
+		if err1 == syscall.EAGAIN {
 			if err1 = c.pollServer.WaitWrite(c); err1 == nil {
 				continue
 			}